Annotate FixtureRequest.node as Any and document why

changelog/13888.improvement.rst

@@ -0,0 +1 @@
+:attr:`FixtureRequest.node <pytest.FixtureRequest.node>` is now explicitly annotated as returning ``Any``, so strict pyright no longer reports it as ``Unknown``. The return type stays deliberately broad, see :issue:`13888`.

src/_pytest/fixtures.py

@@ -564,9 +564,18 @@ def fixturenames(self) -> list[str]:
         result.extend(set(self._fixture_defs).difference(result))
         return result
 
+    # The return type is intentionally ``Any``.
+    # The concrete node type depends on the request scope, so the only correct
+    # annotation would be a broad one (``Item | Collector``). That would force
+    # users to ``assert isinstance(...)`` or ``cast`` whenever they know the
+    # actual type (e.g. ``request.node.function`` in a function-scoped
+    # fixture), so we trade type safety for convenience here.
+    # It is spelled out explicitly because pyright in strict mode reports an
+    # unannotated return as ``Unknown`` rather than ``Any``.
+    # See https://github.com/pytest-dev/pytest/issues/13888#issuecomment-3511168937.
     @property
     @abc.abstractmethod
-    def node(self):
+    def node(self) -> Any:
         """Underlying collection node (depends on current request scope)."""
         raise NotImplementedError()